Tachometer

[relative4]

My engine is now running, and one of the upcoming steps will be to recalibrate the tachometer.  I found a thread on this site that mentions, in addition to Leon Zaks' site, a 2000 edition of the British V8 newsletter containing an article on this task.  That article doesn't seem to have been computerized on this site yet, anyone know how I can get my hands on it?

Alternatively, can anyone make recommendations for aftermarket V8 tachs that will fit the '80 MGB's dash?

Thanks!

[Moderator]

How To Sponsor Digitization of Back-Issue Articles

[Citron]

Billy,
I use Classic Instruments tachs and speedos.  I have not done an 80 but have done a 70, 74, 67 and an 85 Jag.
They are on the web but I don't have the address.
Good people to work with.

Steve

[kstevusa]

Billy, I did my conversion using the updated instructions in the V8 Magazine article and also referred to Zak's.  it was simple because i am not a electronic wizzard.   I did drill a small hole in the case and mount the p-ometer  (can't spell) on the outside of the case for ease of calibration.  I just used a V8 tach and adjusted the MG to the know working V8 tach reading.  Maybe a Google search will turn up the old article.  just be sure the revised version is one you use.

[302GT]

VDO tachometers fit and look similar to the original. VDO is one of the only companies that makes a 4 inch diameter tach (and speedometer) that fit in the late style dashboards. The black rims on the VDO instruments can be cut off and replaced with chrome rings from the original gauges. The only other source for 4 inch gauges that I know of is Smiths who makes Cobra reproduction instruments.  

If you have the smaller instruments (pre 1977), then just about any manufacturer makes gauges in that size.

[Moderator]

Thanks to Billy's generous sponsorship, the original article has now been digitized!

Here's a direct link:
<a href="http://www.britishv8.org/Articles/MGB-to-V8-Tach-Conversion.htm">Converting the MGB Tachometer to V-8 Calibration by Kurt Schley</a>

[MGBV8]

Curtis,

If you are going to put that out there for all the world to read, you really need to include the correction article that is in the next issue.

The drawing in figure 1 is incorrect.  The trim pot is actually soldered across pins 3 & 8.  Leon's pictures show that while he did solder the pot to the correct legs, he calls them pins 4 & 7. So, the pics are correct, but the drawing is wrong.

[camaroneil]

i was just about to query that,
thanks for the correction,
i'm trying mine today,

many thanks,
neil

[Bill Young]

I wonder if Kurt would have the information on the component size to adapt for a 6 cylinder?
By the way, does anyone know how to adapt the early current loop style tach for either V8 or V6 use?

[BlownMGB-V8]

Bill, I did mine using Theo's replacement board but I think Kurt's tach driver mod would work just as well. You no longer use the loop, but it wasn't that great anyway.

Jim